A gyratory crusher of the kind stated above can be used for crushing, for example, ore and stone material into smaller size.
WO 99/22869 discloses a gyratory crusher, in which a crushing head is mounted on a gyrating vertical shaft. At its lower end the vertical shaft is supported on a thrust bearing including three horizontal bearing plates. A first bearing plate is attached to the vertical shaft, a second bearing plate is attached to a piston arranged below the vertical shaft, and a third bearing plate is slideably and rotatably arranged between the first and second bearing plates. The first and second bearing plates are generally made of a bearing metal, such as bronze, and the third bearing plate is often made of steel. The piston arranged below the vertical shaft is included, together with a cylinder, in a hydraulic piston arrangement by way of which the vertical position of the vertical shaft can be displaced for the purpose of setting a desired crushing gap between the first and second crushing shells.
A drawback of the crusher described above is that the present type of thrust bearing is expensive to manufacture and that the horizontal bearing plates included therein are subjected to considerable wear, which necessitates frequent replacement of the thrust bearing at a high cost. Moreover, a large amount of heat is generated in the thrust bearing and this heat must be cooled off by way of oil, which in turn needs to be cooled.